Method for quantification of stratum corneum hydration using diffuse reflectance spectroscopy

US6668181B2 · kind B2 · utility

Assignee

• Sensys Medical, Inc. · US

Inventors

• Brian Jeffrey Wenzel · San Jose, US
• Stephen Monfre · Gilbert, US
• Timothy L. Ruchti · Gurnee, US
• Ken Meissner · Gilbert, US
• Frank Grochocki · Phoenix, US
• Thomas B. Blank · Chandler, US
• Jessica Rennert · Scottsdale, US

Key dates

• Filing date: May 31, 2002
• Grant date: Dec 23, 2003
• Expiry date: May 31, 2022

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61B2560/0233
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An apparatus and method for non-invasively quantifying the hydration of the stratum corneum of a living subject utilizes in vivo spectral measurements made by irradiating skin tissue with near infrared (NIR) light. The apparatus includes a spectroscopic instrument in conjunction with a subject interface. The resulting NIR absorption spectra are passed to an analyzer for further processing, which includes detecting and eliminating invalid spectral measurements, and preprocessing to increase the signal-to-noise ratio. Finally, a calibration model developed from an exemplary set of measurements is applied to predict the SC hydration for the sample. The method of SC hydration measurement provides additional information about primary sources of systematic tissue variability, namely, the water content of the epidermal layer of skin and the penetration depth of the incident light. The stratum corneum hydration measurement is therefore suitable for further spectral analysis and the quantification of biological and chemical compounds, such as blood analytes.